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Document Type

Thesis - University Access Only

Award Date

2014

Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

First Advisor

Jikai Du

Abstract

Various ultrasound techniques are widely used in the nondestructive testing (NDT) field and have seen a number of successful applications, such as for flaw detection and material property evaluation of composite materials. In conventional ultrasound testing, a single-element transducer is usually moved mechanically in a time consuming pattern and sometimes several such transducers are required to focus ultrasound energy at different depth in inspected material. On the other hand, phased array ultrasonic inspection is an emerging NDT technology which has a series of ultrasonic elements from 16 to as many as 256 or even more and is able to pulsing each small individual elements separately, and offers means to focus the ultrasonic beam at different locations and steer it to reach defects at hidden parts in complex structures, hence, substantially reducing the scanning time and simplifying the scanning pattern by scanning electronically in shorter time. As a result, more signal focusing, wide range of beam angle and sweeping characteristics of the beam can be achieved by phased array ultrasonic method and this makes the ultrasonic phased array method an alternative but more powerful solution for composite material inspection.In this research the ultrasonic phased array method was used for composite material inspection. The set of complex phased array parameters were set up to generate the required wave types. Then, for more specific type of inspection, plate wave was generated using the phased array technology, to evaluate the behavior of this kind of wave and inspection parameters and capability of flaw detection. Finally, to reach the goal of flaw detection, a series of artificial holes were made on the composite plates and generated ultrasonic phased array plate wave was used to detect the flaws and evaluate the detection characteristics.

Library of Congress Subject Headings

Composite materials -- Nondestructive testing
Ultrasonic testing

Description

Includes bibliographical references (pages 100-102)

Format

application/pdf

Number of Pages

141

Publisher

South Dakota State University

Rights

In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/

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